/* report char in a string with most occurrence*/




import java.util.*;
import java.io.*;
class main {
	//using HashMap 
	static char mostCommonChar(char array[]) {
		HashMap<Character, Integer> map = new HashMap<Character, Integer>();
		for(char c : array) {
			map.put(c, map.get(c) == null ? 1 : map.get(c) + 1);
		}

		char mostCommon = array[0];
		for(char c : map.keySet()) {
			if(map.get(c) > map.get(mostCommon))
				mostCommon = c;
		}
	return mostCommon;	

	}
		

		
		


	public static void main(String argv[]) throws IOException{
		BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
		char array[];// = new char[10];
		System.out.println("enter string:");
		//try {
			array = stdin.readLine().toCharArray();
		//} catch (IOException e) {
		//}

		System.out.print("Most common char is: ");
		System.out.print(mostCommonChar(array));
	}
}

